Flight test robust determination method for equivalent man-machine closed loop characteristic of statically unstable aircraft

Abstract

The invention discloses a method for determining the equivalent aeroservoelasticity (ASE) robust stability of a statically unstable aircraft through a flight test, which is used for solving the technical problem of large modeling errors of the conventional flight test determination method. The technical scheme is that: a closed loop transfer function frequency characteristic matrix of a multi-loop system of the statically unstable aircraft can be obtained through a sweep frequency flight test; a relational expression between a closed loop transfer function and ASE stability is established according to a corresponding relation between the closed loop transfer function and an open loop transfer function; and the closed loop transfer function frequency characteristic matrix of the system is subjected to characteristic decomposition, and a multi-loop stability margin analysis scalar equation is obtained according to the critical stability condition of the system, so that the ASE stabilityof the whole loop is calculated, and problem difficulty is greatly simplified.

Description

technical field [0001] The invention relates to a flight test determination method of flight quality, in particular to a flight test robust determination method of equivalent man-machine closed-loop characteristics of statically unstable aircraft. Background technique [0002] In the development of high-performance aircraft, the evaluation of the flight quality of an aircraft depends not only on the dynamic characteristics of the aircraft itself and the pilot's control, but also on the highly consistent cooperation between the pilot and the aircraft, as well as the relationship between the pilot and the aircraft. Rationality of function allocation among advanced aircraft flight control systems. Until 1980, the US military standard for evaluating aircraft flight quality still had serious flaws, that is, it did not consider the role of the pilot in the control circuit, so there was still a certain gap between the evaluation obtained from this and the results obtained by the te...

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the shortcomings of large modeling errors in the existing flight test determination methods, the present invention provides a flight test robust determination method for the equivalent human-machine closed-loop characteristics of statically unstable aircraft. The frequency characteristic matrix of the closed-loop transfer function of the multi-loop system of the stabilized aircraft, according to the corresponding relationship between the closed-loop transfer function and the open-loop transfer function, expresses the closed-loop system composed of the man-machine model and the aircraft into an equivalent equation, through multi-input- The eigendecomposition of the closed-loop frequency matrix of the multi-output system, and according to the critical stability of the system, the static gain of the driver link, the inherent delay characteristics, the lead compensation time constant, and the driver lag compensation time constant can be directly determined by the multi-parameter analysis method. The impact of the system stability margin, so as to determine whether the man-machine characteristics of the aircraft can meet the requirements of the national military standard stability margin

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